Ball for ball game and method for manufacturing the same

ABSTRACT

The ball for a ball game of the invention includes a fabric layer ( 1 ) having a spherical 12-hedron where twelve right pentagonal fabric pieces ( 2 ) are sewn together. The marginal edges of the fabric piece being folded by 90 degrees, and the marginal edges are sewn together with a sewing machine. The fabric layer is then reversed through cross-like slits ( 5   a,    5   b ) formed in the fabric layer in a location opposite to a valve opening ( 5 ) (also formed in the fabric layer) in such a manner that the marginal edges are located on an inner side of the fabric layer. After the bladder is accommodated within the fabric layer through the closure hole ( 5 ), the hole ( 5 ) is closed by a patch. Onto a surface of the fabric layer, there is adhered the panels. Thereby, the ball for a ball game having no unevenness and soft feeling is attained.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the national stage of International (PCT) PatentApplication Ser. No. PCT/JP2002/013351, filed Dec. 20, 2002, thedisclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a ball for ball game and method formanufacturing the same.

BACKGROUND ART

Conventionally, a ball for ball game having a construction, where air isconfined, includes a bladder made of rubber where air is confined; areinforcing layer formed outside the bladder, by which sphericality anddurability are applied to the ball; and a skin layer composed of aplurality of panels adhered onto the reinforcing layer.

There is known from the U.S. Pat. No. 4,856,781 such a reinforcing layeras to be composed of twelve fabric pieces, peripheral parts of which aresewn together to obtain a spherical shape. By virtue of the reinforcinglayer, there is attained a ball where user can have an extremely softfeeling by sewing the twelve fabric pieces together to obtain a fabriclayer in such a manner that only one side of the twelve fabric pieces isnot sewn, and the only one side serves as a hole for introducing abladder, reversing the fabric layer through the hole, positioning amarginal part of the hole to be located inside, introducing the bladderinto the fabric layer, and sewing the hole while positioning themarginal part outside.

In the U.S. Pat. No. 4,239,568, there is disclosed a technique where aspherical fabric layer is formed by adhering a plurality of fabricpieces onto a spherical hollow body made of paraffin, forming an openingin one of the plurality of fabric pieces, collapsing the plurality ofthe spherical hollow body into pieces, removing the collapsed piecesfrom the opening, and inserting a bladder through the opening.

Also, there is known a ball generally called a hand stitched ball e.g.from the U.S. Pat. No. 3,119,618. This ball is obtained by sewing thepanels in such a manner that adjacent marginal edges of the panels arefolded inward and sewn together to form a spherical body, and insertinga bladder into the spherical body.

In the sewn ball, a member called a backing member made of fabric isadhered to each of the panels. There is no reinforcing layer made ofe.g. fabric covering the bladder.

In the construction disclosed in the above-mentioned the U.S. Pat. No.4,856,781, the marginal part to be sewn for the hole for accommodating abladder is located outside, whereby the spherical shape is prevented tobe formed. That is, fine unevenness appearing on the surface through thepanels due to the marginal part to be sewn. This phenomenon is generallyknown as the mirror-through effect, and causes the balls to be swayed.

In the fabric layer disclosed in the U.S. Pat. No. 4,239,568, the fabricpieces are adhered onto the spherical hollow body in such a manner thatthe marginal edges of adjacent fabric pieces are superimposed. Thesuperimposed parts prevent the ball from forming a spherical shape, andfine unevenness appears on the surface of the panel. In the constructionof the U.S. Pat. No. 4,239,568, the fabric pieces are not sewn together.There is not any knowledge in which the fabric layer is reversed.

Normally, a valve is the biggest element in essential elements of thebladder. In order to insert the bladder into the spherical fabric layer,the hole is required to have a size where the valve can be passedthrough the hole. That is, preferably the hole has a diameter of about15 mm. The bladder is made of rubber, and have an elasticity.Accordingly, the elements of the bladder other than the valve can beeasily passed through the hole by expanding and stretching them.

On the other hand, when the fabric layer is reversed, the hole isrequired to have a minimum diameter of about 20 mm even in the case ofclass 3 of the soccer ball which is the smallest soccer ball. The sizeof the hole for reversing the fabric layer is different from that foronly inserting the bladder. The hole for reversing the fabric layer inthe soccer ball is required to have substantially the same size as thesize of the hole for reversing the fabric layer in the volley ball. Thehole for reversing the fabric layer in the basket ball is required tohave a size larger than the size of the hole for reversing the fabriclayer in the soccer ball.

In the construction of the ball disclosed in the U.S. Pat. No.4,239,568, the superimposed parts of the fabric pieces contribute to themirror-through effect, and in order to reduce the mirror-through effectthere is employed such a construction where the superimposed parts ofthe fabric pieces correspond to the boundaries of the panels.Nevertheless, it is impossible to completely remove themirror-througheffect.

Further, as described in the U.S. Pat. No. 3,119,618, in the sewn ballhaving no spherical reinforcing layer the tensile strength in the partwhere the adjacent panels are sewn together is different from that inthe center part of each of the panels, because the parts where theadjacent fabric pieces are sewn together using threads have a higherstrength. For that reason, there is the problem that a ball having highsphericity cannot be obtained, because the central part of the panelsare expanded. Further, the sphericity of the ball depends largely on thestrength of the thread used for sewing the panels together. It is almostimpossible to obtain the ball having homogeneous strength because of aworkmanship, or a dispersion of the tensile strength even by the sameworkman.

The present invention was made in view of the circumstances as mentionedabove. The object of the present invention is to provide a method formanufacturing a ball having a spherical fabric layer comprising aplurality of fabric pieces by which a sphericity is significantlyimproved, providing a hole for reversing the fabric layer through thehole in the case where all of the parts (for instance marginal parts ofthe plurality of fabric pieces) which prevent the sphericity are locatedinside to make the surface of the fabric layer completely spherical, themirror-through effect is prevented from occurring, and accommodating abladder through the hole; and a ball for ball game manufactured by themethod.

DISCLOSURE OF INVENTION

One aspect of the invention is method for manufacturing a ball for ballgame, said ball comprising:

(a) a bladder including a valve for introducing air into said bladder;

(b) a fabric layer located outside said bladder comprising a pluralityof fabric pieces,

wherein marginal edges of each of said plurality of fabric pieces isinwardly folded,

wherein one of said marginal edges of one of said plurality of fabricpieces and one of said marginal edges of the other one of said pluralityof fabric pieces adjacent to said one of said plurality of fabric piecesare sewn together by a sewing machine to form a spherical shape,

wherein a valve opening is formed in one of said plurality of fabricpieces, and a hole for closure sewing to reverse said fabric layer andaccommodate said bladder is formed in the other one of said plurality offabric pieces opposed to said one of said plurality of fabric pieces;and

(c) a skin layer located outside said fabric layer, said skin layercomprising a plurality of panels;

said method comprising steps of:

(i) superposing said marginal edge of one of said plurality of fabricpieces with said marginal edge of the other one of said plurality offabric pieces adjacent to said one of said plurality of fabric pieces,sewing the same together by a sewing machine, and locating said marginaledge on an outside to form a spherical fabric layer;

(ii) reversing said fabric layer through said hole for accommodatingsaid bladder to locate said marginal edge on an inner side;

(iii) accommodating said bladder through said hole for accommodatingsaid bladder within said fabric layer;

(iv) closing said hole for accommodating said bladder; and

(v) forming said skin layer on an outer surface of said fabric layer.

By this method, a surface of the fabric layer can be a flattened plainwhere there is no unevenness on the surface, and mirror-through effectcan be completely avoided.

Preferably, a patch is abutted onto a peripheral part of said hole foraccommodating said bladder, and said patch is adhere to said fabricpiece whereby said hole is closed. Thereby, the patch is adhered to thefabric layer with adhesive to close the hole, spherical fabric layer iscompleted, and the hole is located to oppose to the valve. As a result,the patch serves as a means for balancing the weight to the valve.

Preferably, a patch is abutted onto a peripheral part of said hole foraccommodating said bladder, said patch is sewn together with said fabricpiece by a sewing machine through a valve opening formed in said fabriclayer. Thereby, the patch is sewn together with the fabric layer toclose the hole, the spherical fabric layer is completed, and the hole islocated to oppose to the valve. As a result, the patch serves as a meansfor balancing the weight to the valve.

Preferably, a patch is abutted onto a peripheral part of said hole foraccommodating said bladder, said patch is sewn together with said fabricpiece by hand stitch to close the hole. In that case, valve opening isused.

Preferably, said hole for accommodating said bladder is comprised of twoslits perpendicularly crossed to each other, said slits have a minimumlength of 20 mm and a maximum length where a minimum distance from aleading end of said slits to an edge of said fabric piece is set under acondition that said minimum distance is at least 10 mm, and wherein saidlength of said slits is ranged between the minimum length and themaximum length. Thereby, the hole is formed into a cross-like-shapedslit, and the cross-like-shaped slit can be completely closed. As aresult, the strength in the patch is constantly maintained, thespherical shape can be maintained, even if the fabric layer is subjectedto pressure from the bladder. Because, if the hole has a circular shape,the strength in the circular hole is smaller than that in the peripheryof the circular hole where the patch is superimposed with the fabriclayer. The patch located inside the circular hole might be expanded dueto the pressure from the bladder.

Since the length of the slit is defined to have a range as mentionedabove, reversing procedure of the fabric layer can be performed by theminimum length, and lowering of the strength caused by the formation ofthe slit can be prevented by the maximum length.

Preferably, said hole for accommodating said bladder is closed throughsaid valve opening by a sewing machine. Thereby, by the sewingprocedure, the hole is closed to complete a spherical fabric layer, therestitution property and the flexibility of the parts which are sewntogether are maintained in the same values of the periphery of the slit.

Preferably, said fabric layer is comprised of twelve right pentagonalfabric pieces. Thereby, twelve right pentagonal fabric pieces are sewntogether to form a right dodecahedron (12-hedrodn). As a result, aspherical body is obtained by spherically and outwardly deforming eachplain constituting the right dodecahedron. In the spherical fabric layerof the right dodecahedron, a spherical body is obtained without applyingbig strain to the spherical piece under the condition that seam linesare equally scattered on a spherical surface. Further, number of thesewing line can be reduced, so that sewing procedure can be performed ina reduced time.

Preferably, said fabric piece is comprised of two fabric pieceslaminated to each other, a warp direction of one of said two fabricpieces is perpendicular to a warp direction of the other one of said twofabric pieces. In a case of a single layered fabric piece in theconventional ball, tensile strength of the warp direction is differentfrom that of the weft direction (normally, tensile strength of the warpdirection is bigger than that of the weft direction). By virtue of theconstruction having two layered fabric piece (i.e., superimposed twofabric pieces) of the invention, the strength of the warp direction issubstantially the same as that of the weft direction. Two fabric piecesare superimposed under the condition that the warp direction isperpendicular to the warp direction. Thereafter, the superimposed fabricpieces are adhered to each other by subjecting to immersion with latexpaste.

Preferably, said each of said plurality of panel is comprised of asurface layer and a shock absorbing layer adhered to a rear surface ofsaid surface layer, wherein marginal edge of said surface layer isinwardly circularly turned by 90 degrees, whereby a side surface of saidshock absorbing layer is covered with said inwardly turned marginaledge, and wherein said panel is adhered to said fabric layer withadhesive. Thereby, the cushion property of the panels are improved bythe shock absorbing layer. In the connecting part between the adjacentpanels, there is formed a steep grooves having V-like shape in sectionwhich are found in a conventional hand stitched ball where panels aresewn together in such a manner that marginal edges of the panels arecircularly folded by 90 degrees and the marginal edge of one of thepanels is sewn together with the marginal edge of the other one of thepanels adjacent to said one of the panels. The gripping property of theball is improved and air resistance is lowered by the grooves.

Preferably, said inwardly turned marginal edge of one of said pluralityof panels is adhered to said inwardly edge of the other one of saidplurality of panels adjacent to said one of said plurality of panelswith adhesive. Thereby, the connecting face of adjacent panels arefirmly connected without generating any gap.

Preferably, said skin layer is formed by superposing two panels, sewingmarginal edge of said superimposed panels, and turning circularly saidmarginal edge by 90 degrees which are sewn together in such a mannerthat said marginal edge is located on an inner side. Thereby, sewingquality such as sewing strength between adjacent panels can be stable.

Preferably, said turned skin layer is adhered to said fabric layer withadhesive. Thereby, the connecting face of adjacent panels are firmlyconnected without generating any gap.

Another aspect of the invention is method for manufacturing a ball forball game, said ball comprising:

(a) a bladder including a valve for introducing air into said bladder;

(b) a fabric layer located outside said bladder comprising a pluralityof fabric pieces,

wherein marginal edges of each of said plurality of fabric pieces isinwardly folded,

wherein one of said marginal edges of one of said plurality of fabricpieces and one of said marginal edges of the other one of said pluralityof fabric pieces adjacent to said one of said plurality of fabric piecesare sewn together by a sewing machine to form a spherical shape, and

(c) a skin layer located outside said fabric layer, said skin layercomprising a plurality of panels;

said method comprising steps of:

(i) forming a hole in one of said plurality of fabric pieces;

(ii) superposing said marginal edge of one of said plurality of fabricpieces with said marginal edge of the other one of said plurality offabric pieces adjacent to said one of said plurality of fabric pieces,sewing the same together by a sewing machine, and locating all of saidmarginal edges on an outer side to form a spherical fabric layer;

(iii) reversing said fabric layer through said hole, and locating all ofsaid marginal edges on an inner side, said marginal edge serving as apart to prevent said fabric layer from spherically forming, and allowingouter surface to be a completely smooth spherical surface;

(iv) accommodating said bladder within said fabric layer through saidhole;

(v) abutting a patch on said hole from an inside of said fabric layer toclose said hole; and

(vi) forming said skin layer on an outer surface of said fabric layer.

Thereby, in the surface of the fabric layer there are completelyeliminated fine level differences caused by partial superposing of thefabric pieces and unevenness. As a result, high sphericity can beattained throughout the fabric layer, and smooth spherical surface canbe achieved in all of the surface on the fabric layer. Also on the skinlayer comprising the panels formed on the fabric layer, fine leveldifferences and unevenness can be prevented from generating.

The other aspect of the invention is a ball for ball game comprising:

a bladder including a valve for introducing air into said bladder;

a fabric layer located outside said bladder; and

a skin layer located outside said fabric layer, said skin layercomprising a plurality of panels;

wherein said fabric layer is comprised of a plurality of fabric pieceswhich are spherically connected with each other;

wherein all parts to prevent said fabric layer from forming a sphericalshape are located on the inner side of said fabric layer, said partsbeing formed in a part where said plurality of fabric pieces arespherically connected;

wherein said bladder is deformed in response to said parts to preventsaid fabric layer from forming a spherical shape, and said parts toprevent said fabric layer from forming a spherical shape are absorbed,whereby an outer surface of said fabric layer having a completespherical shape is maintained without affecting of said parts to preventsaid fabric layer from forming a spherical shape, such that an outersurface of said skin layer having a complete spherical shape ismaintained.

Thereby, in the surface of the fabric layer there is no fine unevennesscaused by e.g. partial superposing of the fabric pieces, andcorrespondingly on the surface of the skin layer there is no fineunevenness. As a result, the ball having a spherical surface with highprecision can be attained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing a fabric layer of a ball for ballgame of the invention;

FIG. 2 is a cross sectional view taken on line II-II of FIG. 1;

FIG. 3 is a cross sectional view cut along a circumference correspondingto a line A in FIG. 1;

FIG. 4 is a front view of a closing structure of a fabric piece seenfrom an inside of the ball, said fabric piece having a slit-like shapedhole for reversing the fabric layer and accommodating a bladder;

FIG. 5 is a cross sectional view taken on line of V-V of FIG. 4;

FIG. 6 is a front view of another closing structure of a fabric pieceseen from an inside of the ball, said fabric piece having a slit-likeshaped hole for reversing the fabric layer and accommodating a bladder;

FIG. 7 is a cross sectional view taken on line of VII-VII of FIG. 6;

FIG. 8 is a perspective view showing a patch of another embodiment ofthe invention;

FIG. 9 is a front view of still another closing structure of a fabricpiece seen from an inside of the ball, said fabric piece having aslit-like shaped hole for reversing the fabric layer and accommodating abladder;

FIG. 10 is a perspective view showing a state where two fabric piecesare not yet adhered to each other;

FIG. 11 is a front view showing the fabric piece;

FIG. 12 is a cross sectional view for explaining how to sew the fabricpieces together;

FIG. 13 is a cross sectional view showing a construction where thefabric piece is sewn with the patch;

FIG. 14 is a perspective view showing a fixture;

FIG. 15 is a cross sectional view showing a valve of the bladder and thefabric layer;

FIG. 16 is a perspective view showing a completed state of the ball;

FIG. 17 is a cross sectional view taken on line of XVII-XVII of FIG. 16;

FIG. 18 is a cross sectional view showing another construction of a skinlayer; and

FIG. 19 is a cross sectional view showing an unfolded state of a panelhaving a construction shown in FIG. 18.

BEST MODE FOR CARRYING OUT THE INVENTION

The embodiment to which the invention is applied will be explained withreference to the drawings.

In FIGS. 1 to 3, numeral 1 denotes a fabric layer where twelvepentagonal fabric pieces 2 are sewn together to form a spherical shape.The fabric layer 1 serves as a reinforcing layer. Marginal edge of thefabric piece 2 is folded inward by 90 degrees. The folded part of onefabric piece 2 and the folded part of the other fabric piece 2 are sewntogether with thread 3. The fabric layer 1 is spherically formed havinga construction of a regular dodecahedron sewn together by a sewingmachine.

Numeral 4 denotes a valve opening formed at the center of one of thefabric pieces 2, the valve opening having a diameter of about 10 mm.When a needle for introducing air is inserted into the valve, air isintroduced into the bladder.

Numeral 5 denotes a hole formed at the center of the fabric piece 2opposed to the fabric piece 2 where the valve opening 4 is formed. Thehole 5 is comprised of a slit 5 a and a slit 5 b which is perpendicularto the slit 5 a. That is, the hole 5 is a cross-like shaped slit. Thehole 5 is used for the hole for reversing the fabric layer 1 and a holeaccommodating the bladder into the fabric layer 1. In FIG. 1, theconnection between adjacent fabric pieces 2 on the back surface of thefabric layer is denoted by a dashed line C.

In order to reverse the fabric layer 1 (i.e., make the fabric insideout), as a minimum length the slit 5 a and the slit 5 b have necessarilya length of 20 mm respectively, even in the case of the ball having adiameter of about 19 cm, the ball is called as class-3 soccer ball usedby students of elementary schools. If the length is smaller than 20 mm,then the reversing procedure is difficult to be performed. In the caseof ball having a diameter of about 22 cm (so-called a class-5 soccerball) which is mainly used by adult players, the slit 5 a and the slit 5b have necessarily a length of at least 40 mm respectively. The longerthe length of the slits 5 a, 5 b, the lower the strength of the fabricpiece 2 although the reversing procedure is easier. For that reason, itis not preferable to have slits 5 a, 5 b with a length longer than theminimum length required for the reversing procedure.

That is, in order to maintain the desired strength of the fabric piece2, the maximum length of the slits 5 a, 5 b is determined by the need tohave a minimum distance s of about 10 mm between the end P1 of the slits5 a, 5 b and the point P2 which is located on the peripheral edge of thefabric piece 2 (see FIG. 4). Then, the length of the slits 5 a, 5 b isset between the maximum length and the minimum length. If the length ofdistance s is less than 10 mm, then the strength of the fabric piece isdecreased and there is the possibility that a breakage is generated inthe portion located between the point P1 and the point P2 as the soccerball is repeatedly used.

For instance, in the case of the class-5 soccer ball, a side of thefabric piece 2 has a length of 76 mm. In that case, a circle inscribedwith an outline of any one of fabric pieces 2 has a diameter of 53.2 mm.Then, in the condition that the value of s is 10 mm, the maximum lengthof the slits 5 a, 5 b is about 84 mm. In this embodiment (i.e., theclass-5 soccer ball), the hole 5 is comprised of the slit 5 a and theslit 5 b which is perpendicularly crossed with the slits 5 having thelength of 50 mm at the center of the slits 5 a, 5 b to form a cross-likeshape.

Further, in the condition where the fabric layer 1 is comprised oftwelve pentagonal fabric pieces and twenty hexagonal fabric pieces toform a semi-regular dotriacontahedron, a cross-like shaped slit isformed at the center of one of the twenty hexagonal fabric pieces andthe value of s is 10 mm, the maximum length is about 58 mm.

The hole 5 is required to be completely closed by sewing the peripheralpart of the slits. For that reason, the slit-like shaped hole ispreferable rather than circular-shaped hole. That is, if the circularshape is employed as a shape of the hole 5, a patch which is locatedwithin the circular-shaped hole is subjected to a pressure of thebladder. Thereby, the patch is expanded, so that the spherical shape ofthe fabric layer 1 is not possibly maintained. On the other hand, if theslit-like shape is employed as a shape of the hole 5, spherical shape ofthe fabric layer 1 is possibly maintained. Further, the greater thenumber of slits, the less the strength of the fabric piece 2.Accordingly, two slits 5 a, 5 b which bisect each other at right anglesis the most preferable.

Besides, if the hole 5 is comprised of the slits 5 a, 5 b having alength within the above-mentioned range, the bladder is easilyaccommodated into the reversed fabric layer 1. As mentioned before, ifthe slits 5 a, 5 b have a length of about 15 mm, the bladder can beaccommodated through the slits. However, the fabric layer cannot bereversed through the slits having a length of about 15 mm.

As shown in FIGS. 4 and 5, the hole 5 in the fabric piece 2 is closed byadhering a patch 6 to the fabric piece 2 from an inner side of thefabric layer 1 with adhesive 7 such as latex paste. The patch 6 is madeof fabric having the same material and construction, where two wovenfabric are adhered to each other, as those of the fabric piece 2, andhas a disc-like shape, diameter of which is about 60 mm. If the patch 6is located outside the fabric layer 1, the patch 6 is protruded by athickness of the patch when the bladder is accommodated, and thereafterthe bladder is inflated with air. As a result, the protruded patchpossibly gives rise to the mirror-througheffect. For that reason, thepatch 6 is located inside the fabric layer 1.

In order to assuredly secure the patch 6 to the fabric piece 2, as shownin FIGS. 6 and 7, there is employed such a construction where the fabricpiece 2 is sewn with the patch 6. That is, after the patch 6 is abuttedto the fabric piece 2 from inside of the fabric layer 1, the patch 6 andthe fabric piece 2 are sewn along the slits 5 a, 5 b, and sewn in aspiral shape using a sewing thread by a sewing machine or a hand. Inthat case, the patch 6 is located inside the fabric layer 1 as mentionedabove.

In FIG. 8, there is shown another embodiment of the patch 6 comprisingtwo discs 6 a, 6 b made of fabric adhered to each other with adhesive. Adiameter of one of the two discs is different from a diameter of theother one of the two discs. Each of the discs 6 a, 6 b has the sameconstruction as the fabric piece 2 where two sheets made of fabric areadhered to each other. For instance, the disc 6 a has a diameter of 60mm and the disc 6 b has a diameter of 40 mm, and the disc 6 a of thepatch 6 is adhered to the fabric piece 2 with adhesive. Since thebalance of the weight of the patch 6 against the weight of the valve ofthe bladder is considered, the disc 6 b is added. The weight of thenormal valve is about 4.5 g. However, the weight of the patch havingonly the disc 6 a is somewhat smaller than 4.5 g. For that reason, theweight of the patch 6 is set in such a manner that the weight of thepatch 6 is equal to that of the valve (I.e., 4.5 g) by adding the disc 6b. Please note that there is achieved such an effect where the balanceof the weight of the patch 6 against the weight of the valve isimproved, even if the patch 6 is composed of only the disc 6 a.

FIG. 9 shows the other construction where the hole 5 is closed by sewingthe fabric piece 2 in such a manner that zigzagged seam is alternate toeach of the slits 5 a, 5 b using a sewing thread 8 without using anyadditional elements such as a patch by means of a sewing machine or handstitching. Normally, sewing procedure can be performed without allowingthe sewing thread loose by a sewing machine whereby a strength ofresulting fabrication is greater than that resulting from handstitching. Accordingly, the fabrication is preferably made by a sewingmachine.

As shown in FIG. 10, the fabric piece 2 of this embodiment is comprisedof two right pentagonal plain woven fabric sheets (hereinafter referredto as pentagonal fabric sheets) 9, 10. The two pentagonal fabric sheets9, 10 are arranged in such a manner that a warp direction a of thefabric sheet 9 are perpendicular to a warp direction a of the fabricsheet 10, and thereafter the fabric sheet 9 is adhered to the fabricsheet 10 with adhesive having tackiness such as latex paste. As aresult, the total tensile strength of the warp direction a of the fabricsheets 9 and 10 is equal to that of a weft direction b of the fabricsheets 9 and 10. Normally, in the plain woven fabric the tensilestrength of the warp is greater than that of the weft direction. Forthat reason, when the plain woven fabric is used under the conditionwhere there is a difference of the strength between the warp directionand the weft direction, the plain woven fabric is extended faster in theweft direction to cause a deformation. Accordingly, the fabric piece 2of this embodiment has a construction as mentioned above.

The fabric piece 2 tends to extend in the direction 45 degrees to thewarp direction a (or the weft direction b) due to a bias effect, theshock applied to the ball is absorbed and relaxed. As the material forthe fabric piece 2, cotton, blend of cotton and polyester, high strengthfiber fabric such as Kevlar (trade name) might be used.

In the embodiment mentioned above, there is explained such a case wherethe fabric piece 2 is comprised of two plain woven fabric sheets 9, 10which are laminated and adhered to each other. The number of plain wovenfabric sheet for constituting the fabric piece is not limited to two,three or more might be used. Please note, if the fabric piece 2 iscomprised of three plain woven fabric sheets, the tensile strength ofthe warp direction a of one of the three plain woven fabric sheets isrequired to be set in such a manner as to be equal to total tensilestrength of the warp direction a of the other two plain woven fabricsheets. Further, the fabric piece 2 is comprised of four plain wovenfabric sheets, it is necessary to arrange the same in such a manner thatthe plain woven fabric sheets having a tensile strength equal to eachother are alternately laminated and adhered to each other, and the warpdirection a of one of the laminated sheets is perpendicular to the warpdirection a of the other one of the laminated sheets adjacent to theabove-mentioned one of the laminated sheets. In short, the fabric sheetsconstituting the fabric piece 2 should be arranged in such a manner thatas the total fabric piece 2, a tensile strength of the warp direction ais equal to a tensile strength of the weft direction b.

As shown in FIG. 11, the fabric piece 2 is constructed to have a rightpentagonal shape, particularly to have such a shape where each of fivesides (or leading edges) is outwardly projected to have such a radius ofcurvature as to obtain a spherical body when the required number of thefabric pieces are sewn together. A length of any one of the five sidesis equal to that of the other one of the five sides. Numeral 11 shows aguiding line for sewing procedure which is printed along the sides, andnumeral 12 shows a marking printed between the guiding line and the sideat each vertex. The marking 12 is used for alignment.

As shown in FIG. 12, after two fabric pieces 2 are superimposed witheach other, the superimposed fabric pieces 2 are located on a sewingtable 13 of the sewing machine, then the superimposed fabric pieces aresewn together along the guiding line 11 with a sewing thread 14consisting of an upper thread 14 a and a lower thread 14 b. Numeral 15shows a sewing needle. If a seam is departed from the guiding line 11, aspherical body as designed cannot be formed from the fabric layer 1. Forthat reason, the seam should be exactly located. The guiding line 11plays an important role for sewing exactly along the prescribed curve.Thus, all of the sides of twelve fabric pieces are sewn together. Atthat time, marginal edges 16 (please see FIG. 3) to be sewn, which arelocated outside the guiding line 11 under such a condition as to befolded at right angle. Please note that the guiding line is not needed,if an electronic sewing machine where any sewing line can be set bymeans of a program.

After the completion of the sewing procedure, the fabric layer 1 isreversed using the hole 5. As a result, the marginal edge 16 (please seeFIG. 3) is locate inside the fabric layer 1. The bladder is accomodatedthrough the hole 5 into thus obtained spherical shaped fabric layer 1.

FIG. 13 shows a construction where a patch 6 is abutted to the inside ofthe fabric layer 1 to cover the hole 5, and the patch 6 and fabric layer1 are sewn together. As shown in FIG. 13, after the bladder 17 isaccommodated into the fabric layer 1, the valve opening 4 located justunder the needle 15 of the sewing machine is engaged with a thin fixture18 (please see FIG. 14) having a cylindrical part, where the cylindricalpart is provided with flange parts on upper and lower side thereof. Theoutside diameter of the cylindrical part is substantially the same asthe diameter of the valve opening 4. A peripheral part of the valveopening 4 is interposed between the flange parts, thereby the valveopening 4 in the fabric layer 1 is fixed just under the needle 15 of thesewing machine. In that condition, the hole 5 in the fabric layer 1 isclosed by the sewing procedure using the sewing thread 14. The procedureis called “closure sewing”. At that time, the bladder 17 is biased toone side of the space within the fabric layer 1, for fear that thebladder 17 may collide against the needle 15. Preferably, the sewingthread, yarn count of which is five, is made of polyester or the like.As mentioned above, the sewing thread 14 is composed of the upper thread14 a located on the upper side of fabric layer 1 and the lower thread 14b located on the lower side of fabric layer 1. By virtue of the closuresewing, the layer 1 can be formed to have a closed spherical shape. Theclosure sewing is performed by not only the sewing machine, but alsohand stitching after the patch 6 is abutted to the inside of the fabriclayer 1. In that case, after a finger is inserted through the hole 5,the fabric layer 1 and the patch 6 are sewn by using a needle whilepinching the fabric layer 1 and the patch 6 by the finger and a thumb.When the hole becomes too narrow to insert the finger, after the fingeris pulled out, the fabric layer 1 and the patch 6 are sewn togetherwhile the fabric layer 1 and the patch 6 are pinched by a finger and athumb, and the patch 6 is abutted to the valve opening 4. Normally, inthe closure sewing there is needed a special sewing machine, of whichconstruction is different from that of the sewing machine used forsewing the other part. However, even in the closure sewing by handstitching, the hole 5 is closed without using the special sewingmachine.

As shown in FIG. 15, the valve 19 and a valve holding part 20 are fixedin the bladder 17, and on a surface located in a peripheral part of thevalve 19 there is provided a disc-like shaped patch 21 adhered to thevalve 19. The valve holding part 20 and the disc-like shaped patch 21are vulcanized so as to be adhered to the bladder 17 while the bladder17 is vulcanized. The valve holding part 20 and the disc-like shapedpatch 21 might be adhered to the bladder 17 with adhesive. After thebladder 17 is vulcanized, the valve 19 is engaged with an opening formedat the center of the valve holding part 20. At the center of the valve19, there is formed an aperture 22 through which air is introduced intothe bladder 17 by means of an air supplying needle which is insertedinto the aperture.

After the hole 5 is closed, the valve 19 is aligned with the valveopening 4, and the disc-like shaped patch 21 is adhered to an inner sideof the fabric layer 1 with adhesive. With regard to a part locatedbetween the fabric layer 1 and the bladder 17 other than the adheredpart, the fabric layer 1 is merely contacted with the bladder 17.

The bladder 17 made of a rubber having no air permeability such as latexrubber, butyl rubber is formed into a hollow spherical body. Airpressure to be set within the bladder 17 is about 1.0 kgf/cm2. The airpressure is achieved by filling air through the air supplying needlefrom an air pump, wherein the air supplying needle is inserted into theaperture 22 formed in the valve 19.

In FIGS. 16, 17, numeral 23 denotes a skin layer comprising twelvepentagonal panels 24 and twenty hexagonal panels 25 adhered onto thefabric layer 1 with adhesive such as chloroprene rubber adhesive,natural rubber adhesive. The whole of a surface of the fabric layer 1 iscompletely covered with the thirty-two panels 24, 25 with no gap. Forthat reason, the marginal edges of one of the panel 24 or 25 iscontacted with the marginal edges of the other one of the panel 24 or25.

Suitable materials for the panels 24, 25, are synthetic leather,polyvinyl chloride resin leather, thermoplastic polyurethane film,polyurethane foam having a polyurethane thin film on a surface thereofand natural leather. The skin layer 23 comprising thirty-two panels 24,25 has such a spherical shape which is obtained by somewhat outwardlyexpanding a semi dotriacontahedron which is a kind of a polyhedron.Numeral 26 denotes a valve opening formed in the hexagonal panel 25. Thevalve opening 26 corresponds to the valve opening 4 formed in the fabriclayer 1.

The panels may alternatively be formed into a right dodecahedron usingtwelve pentagonal panels in the same manner as the fabric layer 1. Also,preferably in that case, each peripheral edge of the panels is curvedoutwardly to obtain a spherical shape.

Preferably, a connecting line 27 of adjacent panels 24, 25 and a seamline 28 of the fabric pieces 2 are arranged in such a manner that theconnecting line 27 is not superimposed on the seam line 28. Each seamline 28 in the fabric pieces 2 has an enough strength to keep the wholefabric pieces spherical, nevertheless the tensile strength of the seamline 28 is smaller than that of peripheral part of the seam line 28.Similarly, the tensile strength of the connecting part of the adjacentpanels 24, 25 located at the connecting line 27 is smaller than that ofthe peripheral part of the connecting line 27. Accordingly, the seamline 28 of the fabric pieces and the connecting line 27 of adjacentpanels 24,25 are arranged in such a manner that the seam line 28 and theconnecting line 27 are crossed and the lower strength parts arescattered on the spherical surface in order to avoid crossing of theseam line 28 and the connecting line 27 as little as possible.

As shown in FIG. 17, the marginal part 16 to be sewn in the fabric piece2 is folded by about 90, so that the marginal part 16 is inwardlyprojected. However, the inwardly projected marginal part 16 ispressurized by the bladder 17 and further folded in such a manner thatthe marginal part 16 is contacted with the rear side of the fabric piece2.

The inwardly projected part is absorbed by a deformation of the bladder17. For that reason, the inwardly projected part does not affect thespherical shape, and a complete spherical surface having no unevennessin the fabric layer 1 is kept smooth. Between the fabric layer 1 and theskin layer 23, a rubber covering layer (not shown) might be interposedin order to enhance the adhesive strength of the fabric layer 1 and theskin layer 23.

Each of the panels 24, 25 is comprised of a leather or leather likesurface layer (hereinafter referred to as surface layer) 29, a panelcloth layer 30 provided on a rear surface of the surface layer 29, and ashock absorbing layer 31 made of a foam material. The marginal edge ofthe surface layer 29 and the panel cloth layer 30 are folded in such amanner that the end of the marginal edge is circularly turned by about90 degrees to the rear side of the skin layer 23. The surface layer 29,the panel cloth layer 30 and the shock absorbing layer 31 are adhered toeach other with adhesive such as latex paste. The side surface of theshock absorbing layer 31 is also adhered to the panel cloth layer 30.The leading edge of the surface layer 29 and the panel cloth layer 30and the rear side of the shock absorbing layer 31 are adhered to thefabric layer 1.

The shock absorbing layer 31 served as not only an element for absorbingand relaxing a shock, but also an element for adjusting a thickness tokeep a thickness of the panels 24, 25 constant. In the connecting part27, there is formed a narrow/steep groove having the same shape as thatof a hand stitched ball with a construction where marginal edges ofadjacent panels are inwardly folded by 90 degrees so as to be sewntogether. In the lower side of the groove, the adjacent surface layers29 are joined to each other, and can be adhered to each other withadhesive. Thereby, the adjacent surface layers 29 in the connecting part27 are closely contacted with each other, any gap between adjacentsurface layers is prevented from generating. As a result, water isprevented from entering. Further, the ball for ball game of thisembodiment has groove similar to that in the hand stitched ball has aneffect where a gripping property is enhanced and the flying distance isincreased.

Further, if corrugated like shaped unevenness is consecutively formed byintermittently subjecting the leading edges which are circularly turnedto high-frequency work or intermittent adhering in such a manner as tobe spaced apart from each other by predetermined distance (about 4 to 5mm), a pseudo sewing line similar to a sewing line of hand-stitched ballcan be obtained.

In addition to the construction of the panel cloth layer 30 and theshock absorbing layer 31, there might be employed such a constructioncomprising a plurality of the panel cloth layers 30 laminated with eachother, or a construction comprising a plurality of the panel clothlayers 30 and a plurality of the shock absorbing layers 31 laminatedwith each other in addition to the construction mentioned above.However, in view of the enhancement of shock absorbing and relaxingeffect, it is preferable to employ the construction where the shockabsorbing layer 31 is interposed between the surface layer 29 and thefabric layer 1.

Suitable materials for the panel cloth layer 30 are woven fabric ornon-woven fabric. The panel cloth layer 30 reinforces the panels 24, 25and the adhering strength of the skin layer 29 and the shock absorbinglayer 31 are improved. However, the panel cloth layer 30 is notnecessarily required, and the panel cloth layer 30 might be omitted, ifan adhesive with a high adhering strength is used.

Suitable materials for the shock absorbing layer 31 are preferably asheet made of foaming material selected from a group consisting ofchloroprene, polyurethane, EPDM, polyethylene, EVA (ethylenevinyl-acetate copolymer), SBR and NR. By adjusting a cushioning propertyof the shock absorbing layer 31, the bouncing height of the ball can beadjusted.

Instead of the panels 24, 25 having the construction mentioned above,the panels which are employed in the conventional laminated ball mightbe used. In that case, marginal edge of the panels are obliquely cutoff, so that in the connecting part of adjacent panels there is formed aV-like shaped shallow groove.

FIG. 18 shows a skin layer having a construction different from theconstruction mentioned above. That is, in this embodiment shown in FIG.18, there is employed such a construction where after two panels 32 aresuperimposed in such a manner that a surface of one of the two panels 32is in contact with a surface of the other one of the two panels 32, thenthe marginal edges of the superimposed panels 32 are sewn together witha sewing machine. The panels 32 might be made from a synthetic leathercomprising a skin layer made of polyurethane where the rear side of theskin layer is reinforced by a non-woven fabric layer. Numeral 33 denotesa needle for a sewing machine, numeral 34 denotes a sewing thread,numeral 35 denotes a shock absorbing layer adhered to the rear surfaceof the panels 32, the shock absorbing layer being made of foamingmaterial. The panels 32 where the marginal edge of the same is sewntogether are unfolded in such a manner that the marginal edge sewntogether is located on the inner side of resulting ball as shown in FIG.19. The marginal edge of any one of the panels 32 is sewn together withthe marginal edge of the other one of the panels 32 adjacent to the oneof the panels 32 to form a spherical skin layer. In that case, closuresewing is performed by hand stitching.

In the conventional hand stitched ball, there is no reinforcing layersuch as a woven fabric layer. For that reason, a so-called backing clothis adhered to the rear surface of each of the panels, so that the panelsdo not bend easily. As a result, such a sewing procedure cannot beperformed with a sewing machine. On the other hand, according to theball of the present invention having the construction as mentionedabove, the fabric layer serving as a reinforcing layer is provided insuch a manner as to cover the bladder. For that reason, on the rearsurface of the panel it is not required to have any woven fabric (aso-called backing cloth), the panel of the present invention is soft andeasy to bend. As a result, the sewing procedure can be performed with asewing machine.

In the construction of the ball of the present invention, the regionwhere the fabric layer is adhered to the skin layer is located only in aperipheral part of the valve opening, and the fabric layer is notadhered to the skin layer in the region other than the peripheral partof the valve opening. That is, the ball of the present invention has agreater part where the fabric piece is not adhered to the skin layer. Inother words, in the greater part the fabric piece is merely coming intocontact with the skin layer. Accordingly, the fabric layer can sliderelative to the skin layer, whereby the shock absorbing properties ofthe ball are improved, and the ball of the present invention can besoftly collided against the human body. Please note that in theconstruction mentioned above, the stitching strength of the skin layerof the present invention cannot be so high as the strength of theconventional hand stitched ball. However, the strength totally requiredas a ball can be maintained, because the fabric layer is defined as thereinforcing layer.

In the foregoing embodiment, the example where the ball of the presentinvention is applied to a soccer ball is explained. The ball of thepresent invention can be applied to any ball having the sameconstruction as that of the present invention, for instance to a volleyball, a handball, a basketball or the like.

INDUSTRIAL APPLICABILITY

According to claim 1 of the invention, all of the marginal edges to besewn are located on the inner side of the fabric layer. Therefore, anyprojected part is not generated on the surface, and a spherical surfacehaving smooth skin layer can be achieved. In the conventional ball, fineunevenness such as projected parts of the marginal edge to be sewnappear on the surface of the fabric layer to give rise to so-called amirror-through effect on the surface of the panels. By virtue of theconstruction of the invention, the ball of the invention can beprevented in such a manner as not to depart from the desired locus ofthe flying ball. Further, the ball having smooth surface is attained andthe appearance of the ball is improved.

Further, according to the invention, the fabric pieces are sewn by asewing machine. For that reason, the sewing procedure is performed in areduced time, and stable quality such as a tensile strength of a sewingthread is attained.

According to claim 2 of the invention, a patch is abutted onto aperipheral part of said hole for accommodating said bladder, and saidpatch is adhered to said fabric piece whereby said hole is closed.Thereby, the fabric layer having closed spherical fabric layer iscompleted. Further, by virtue of the construction mentioned above, thework for closing the hole is easily performed. Further, since the holeis located to oppose to the valve, the patch serves as a means forbalancing the weight to the valve, and the center of gravity of the ballsubstantially corresponds the geometrical center of the ball. As aresult, the ball of the invention can be prevented in such a manner asnot to depart from the desired locus of the flying ball.

According to claim 3 of the invention, said patch is sewn together withsaid fabric piece, the strong bonding strength is attained. Further, thepatch and the fabric piece can be sewn together by a sewing machineunder the condition that a needle of the sewing machine is passedthrough the valve opening. For that reason, the sewing procedure can beeasily performed in a reduced time, and stable quality such as a tensilestrength of a sewing thread is attained. Furthermore, the patch servesas a means for balancing the weight to the valve as mentioned above. Thepatch can be sewn together with the fabric piece by hand stitch asdescribed in claim 4. In that case, any special sewing machine forclosing the hole is not needed.

According to claim 5 of the invention, the cross-like-shaped slit can becompletely closed. As a result, the strength in the patch is constantlymaintained, the spherical shape can be maintained, even if the fabriclayer is subjected to pressure from the bladder. By setting the lengthof the slits in a range where both the requirement (minimum length) forreversing the fabric layer and the requirement (maximum length) forpreventing a degradation of the strength of the fabric layer are met,the spherical fabric layer can be manufactured with relative ease in ashortened time period and without degrading too much the durability ofthe fabric piece with the slit.

According to the claim 6 of the invention, the slit is closed by forinstance such a procedure of sewing alternately the periphery of theslits by a sewing machine. Thereby, by the sewing procedure, the hole isclosed to complete a spherical fabric layer, the restitution propertyand the flexibility of the parts which are sewn together are maintainedin the same values of the periphery of the slit.

According to claim 7 of the invention, said fabric layer is comprised oftwelve right pentagonal fabric pieces. Thereby, twelve right pentagonalfabric pieces are sewn together to form a right dodecahedron(12-hedrodn). As a result, a spherical body is obtained by sphericallyand outwardly deforming each plain constituting the right dodecahedron.For that reason, substantially equal tensile strength is applied to eachside of the 12-hedron, and the sphericity of the ball can be attainedwith high precision.

According to claim 8 of the invention, since the fabric piece iscomposed of at least two sheets of woven fabric laminated to each other,the strength of the warp direction is substantially equal to thestrength of weft direction. As a result, the amount of the deformationin the warp direction is substantially equal to the amount of thedeformation in the weft direction. Accordingly, the spherical shape ofthe fabric layer (i.e., the spherical shape as the ball) is maintainedin the long interval.

According to claim 9 of the invention, the cushion property of thepanels are improved by the shock absorbing layer. In the connecting partbetween the adjacent panels, there is formed a steep grooves havingV-like shape in section. The gripping property of the ball is improvedand air resistance is lowered by the grooves, so that flying distance isincreased.

According to claim 10 of the invention, said inwardly turned marginaledge of one of said plurality of panels is adhered to said inwardly edgeof the other one of said plurality of panels adjacent to said one ofsaid plurality of panels with adhesive. Thereby, the connecting face ofadjacent panels are firmly connected without generating any gap. As aresult, a problem in the conventional ball where rainwater is enteredwithin the ball through the gap to increase the weight of the ball, oranother problem where the panels are easily peeled off is eliminated.

According to claim 11 of the invention, said skin layer is formed bysuperposing two panels, sewing marginal edge of said superimposedpanels, and turning said marginal edge by 90 degrees which are sewntogether in such a manner that said marginal edge is located on an innerside. That is, the formation of the spherical skin layer is performedwithout another element such as a bladder. Such a construction where theskin layer is coming into contact with the bladder can be employed,whereby both the skin layer and the bladder are freely moved, a shockabsorbing property is increased, and soft feeling ball is attained.Further, sewing quality such as sewing strength between adjacent panelscan be stable by means of a sewing machine.

According to claim 12 of the invention, said turned skin layer isadhered to said fabric layer with adhesive. Thereby, the connecting faceof adjacent panels are firmly connected without generating any gap. As aresult, a problem in the conventional ball where rainwater is enteredwithin the ball through the gap to increase the weight of the ball, oranother problem where the panels are easily peeled off is eliminated.According to claim 13 or claim 14 of the invention, in the surface ofthe spherically formed fabric layer there are completely eliminated finelevel differences caused by partial superposing of the fabric pieces andunevenness. As a result, high sphericity can be attained throughout thefabric layer, and smooth spherical surface in any parts of the fabriclayer can be achieved in all of the surface on the fabric layer. As aresult, the sphericity and smoothness of the skin layer formed on thefabric layer comprising the panels are increased, the ball of theinvention can be prevented in such a manner as not to depart from thedesired locus of the flying ball, and the property of controlling theball is attained.

1. Method for manufacturing a ball for a ball game, said ballcomprising: (a) a bladder including a valve for introducing air intosaid bladder; (b) a fabric layer located on an outer surface of saidbladder comprising a plurality of fabric pieces, wherein each of saidplurality of fabric pieces has marginal edges which are folded inwardly,wherein said marginal edges of adjacent fabric pieces are sewn togetherwith a sewing machine, so that said plurality of fabric pieces arejoined to have a spherical shape, wherein a valve opening is formed in afirst one of said plurality of fabric pieces, and a hole for reversingsaid fabric layer and for accommodating said bladder is formed in asecond one of said plurality of fabric pieces wherein the second one ofsaid plurality of fabric pieces is located opposite the first one ofsaid plurality of fabric pieces; and (c) a skin layer located on anouter surface of said fabric layer, said skin layer comprising aplurality of panels; said method comprising the steps of: (i) formingthe fabric layer by superposing two adjacent fabric pieces, sewing alonga marginal edge of the superimposed fabric pieces with a sewing machine,locating said marginal edge on the outer side of the fabric layer andrepeating until all fabric pieces are joined to form a spherical fabriclayer; (ii) reversing said fabric layer through said hole to locate saidmarginal edges on an inner side of the fabric layer; (iii) insertingsaid bladder into the fabric layer through said hole within said fabriclayer; (iv) closing said hole; and (v) forming said skin layer on theouter surface of said fabric layer.
 2. The method of claim 1, wherein apatch is abutted onto a peripheral part of said hole, and said patch isadhered to said second one of said fabric pieces whereby said hole isclosed.
 3. The method of claim 1, wherein a patch is abutted onto aperipheral part of said hole, said patch is sewn to said second one ofsaid fabric pieces with a sewing machine through said valve openingformed in said fabric layer.
 4. The method of claim 1, wherein a patchis abutted onto a peripheral part of said hole, said patch is sewn tosaid second one of said fabric pieces by hand stitching.
 5. The methodof claim 1, wherein said hole comprises two slits, which perpendicularlybisect each other, said slits having a minimum length of 20 mm.
 6. Themethod of claim 1, wherein said hole comprises two slits, whichperpendicularly bisect each other, said slits having a maximum lengthwhich is determined by a distance from ends of said slits to peripheraledges of said second one of said fabric pieces being at least 10 mm. 7.The method of claim 6, wherein said hole is closed through said valveopening using a sewing machine.
 8. The method of claim 1, wherein saidfabric layer comprises twelve right pentagonal fabric pieces.
 9. Themethod of claim 1, wherein each of said fabric pieces comprises twofabric layers laminated to each other, whereby a warp direction of afirst fabric layer is perpendicular to a warp direction of a secondfabric layer.
 10. The method of claim 1, wherein each of said pluralityof panels comprises a surface layer and a shock absorbing layer adheredto a rear surface of said surface layer, wherein marginal edges of saidsurface layer are inwardly turned by 90 degrees, whereby side surfacesof said shock absorbing layer are covered with said inwardly turnedmarginal edges, and wherein said panels are adhered to said fabric layerwith adhesive.
 11. The method of claim 10, wherein an inwardly turnedmarginal edge of one of said plurality of panels is adhered to aninwardly turned edge of an adjacent panel with adhesive.
 12. The methodof claim 1, wherein said skin layer is formed by superposing twoadjacent panels, sewing marginal edges of said superimposed panelstogether, opening out the superimposed panels in such a manner that saidmarginal edges are located on an inner side of the skin layer andrepeating until all the panels are joined to form a spherical skinlayer.
 13. The method of claim 12, wherein said skin layer is adhered tosaid fabric layer with adhesive.
 14. Method for manufacturing a ball fora ball game, said ball comprising: (a) a bladder including a valve forintroducing air into said bladder; (b) a fabric layer located on anouter surface of said bladder comprising a plurality of fabric pieces,wherein each of said plurality of fabric pieces has marginal edges whichare folded inwardly, wherein said marginal edges of adjacent fabricpieces are sewn together with a sewing machine, so that said pluralityof fabric pieces are joined to form a spherical shape; and (c) a skinlayer located on an outer surface of said fabric layer, said skin layercomprising a plurality of panels; said method comprising the steps of:(i) forming a hole in one of said plurality of fabric pieces; (ii)superimposing two adjacent fabric pieces, sewing along a marginal edgeof the superimposed fabric pieces with a sewing machine, locating all ofsaid marginal edges on an outer side of the fabric layer and repeatinguntil all fabric pieces are joined to form a spherical fabric layer;(iii) reversing said fabric layer through said hole, and locating all ofsaid marginal edges on an inner side of the fabric layer; (iv) insertingsaid bladder into the fabric layer through said hole; (v) abutting apatch on said hole from the inner side of said fabric layer to closesaid hole; and (vi) forming said skin layer on the outer surface of saidfabric layer.